Expression dynamics of caveolin-1 in fibroblasts of newborn rats with chronic lung disease and its impact on lung fibroblast proliferation

Abstract Purpose: To evaluate the changes of caveolin-1 in lung fibroblasts in newborn Wistar rats when exposed to hyperoxic conditions, as well as lung fibroblasts cell cycle. Methods: One hundred newborn Wistar rats were randomly divided (50 rats/group) into experimental and control groups, exposed to hyperoxic conditions or normal air, respectively. The fraction of inspired oxygen (FiO2) in the experimental group was 90%, whereas this value was 21% in the control group. Lung fibroblasts were collected on days 3, 7, and 14 of the experiment. Caveolin-1 expression dynamics in lung fibroblasts was assayed in each group by immunofluorescence and Western blot analyses. Flow cytometry (FCM) was used to assess the proportions of lung fibroblasts at different stages of the cell cycle. Results: On day 3, no significant difference in caveolin-1 expression was observed between the hyperoxic and control groups; however, on days 7 and 14, caveolin-1 expression was significantly lower in the hyperoxic group than in the control (P<0.05). No apparent differences were observed in caveolin-1 expression in the control group at the different time points. Using FCM analysis, we showed that the proportion of lung fibroblasts in G0/G1 phase in the hyperoxic group decreased compared to that of the control group on day 7, while the proportion of S-phase cells increased (P<0.05). These differences were more significant when the groups were compared on day 14 (P<0.01). Conclusion: After seven days the exposure to hyperoxic conditions, lung fibroblasts proliferated and caveolin-1 expression decreased.

The mRNA expression of mitogen-activated protein kinase signal pathway related genes in the blood of arseniasis patients caused by burning coal / 中华预防医学杂志

<p><b>OBJECTIVE</b>To detect the mRNA expression of ERK1, ERK2, JNK1 and P38 gene in mitogen-activated protein kinase(MAPK) path way in the arseniasis patients caused by burning coal.</p><p><b>METHODS</b>70 arseniasis patients caused by burning coal at Jiaole village XingRen county in December 2006 were selected as case group, and another 30 villagers with similar living habits, matched gender and age, healthy physical condition without history of burning high arsenic coal were selected as control group from 12 km nearby the same village.Silver diethyl dithiocarbamate method (Ag-DDC) was taken to detect the arsenic contents in the environmental media, food, and arsenic level in the urine and hair of arseniasis patients.On the principle of informed consent, the peripheral blood was collected from the patients. The total RNA was extracted with Trizol method and cDNA was reversed from it. The mRNA expression of ERK1, ERK2, JNK1 and P38 gene in MAPK path way were tested by real-time fluorescent quantitative PCR (QT-PCR).</p><p><b>RESULTS</b>A total of 70 cases of arseniasis patients (31 cases of mild, 25 cases of moderate and 14 cases of severe) and 30 cases of control were chosen. The median (quartile) of arsenic contents in the indoor air, outdoor air, coal, chili and corn were 0.079 (0.053-0.117) mg/m(3) ,0.007 (0.002-0.015) mg/m(3) , 93.010 (39.460-211.740) mg/kg, 3.460(0.550-16.760) mg/kg and 1.500(0.300-4.140) mg/kg respectively. They were above the national health standards. The median (quartile) of arsenic contents in the soil, rice and drinking water were separately 12.130(4.230-24.820) mg/kg, 0.650(0.300-0.980) mg/kg and 0.043(0.012-0.089)mg/kg, which were within the national health standards. Compared with the control group ((26.97 ± 9.71)µg/g Cr), arsenic level in the patients' urine ((71.48 ± 22.74)µg/g Cr) increased significantly, the differences were significant (F = 90.38, P < 0.01). Compared with the control group ((1.58 ± 1.07)µg/g), arsenic level in the patients' hair ((4.45 ± 2.78) µg/g) increased significantly, the differences were significant (F = 48.22, P < 0.01). The relative expression amount of the median(quartile) for ERK2, JNK1 mRNA were 0.0667 (0.0378-0.1371) and 0.0013 (0.0009-0.0025), respectively. Compared with the control group 0.1744 (0.1009-0.1985) and 0.0022 (0.0017-0.0030) , only the decreases of ERK2, JNK1 mRNA expression was significant (χ(2) = 15.10, 14.25, P < 0.01), and no significance in the other index. ERK2 mRNA relative expression for mild, medium and severe groups were separately 0.0818 (0.0408-0.1509) ,0.0582 (0.0154-0.1699) and 0.0588 (0.0399-0.1034) . Compared with the control group (0.1744 (0.1099-0.1985) ), there was significant difference (Z = -2.89, -3.19, -2.67, P < 0.01). JNK1 mRNA relative expression were 0.0012 (0.0007-0.001 57), 0.0019 (0.0011-0.0035), 0.0013 (0.0010-0.0026), respectively. Compared with the control group (0.0022 (0.0017-0.0030) ), significances were found in the mild groups (Z = -3.72, P < 0.01).</p><p><b>CONCLUSIONS</b>Arsenic could induce the changes of ERK2 and JNK1mRNA expression in the MAPK path way in arseniasis patients.It suggests that the MAPK signaling pathway take part in the occurrence and development process of arseniasis caused by burning coal.</p>

Relationship of DNA methylation, mRNA transcription and protein expression of glutathione-S-transferases-P1 gene and coal-pollution-borne endemic arsenism / 中国地方病学杂志

Objective To investigate DNA methylation in the promoter region,mRNA transcription and protein expression of glutathione-S-transferases-P1 (GSTP1) gene and their relation with arsenism.Methods In endemic coal-pollution-borne arsenism area,Jiaole village of Xinren county,Guizhou province,according to the diagnostic criteria of endemic arsenism(WS/T 211-2001),123 cases with endemic arsenism were selected and divided into three groups (mild arsenism group:42 cases,moderate arsenism group:41 cases and severe arsenism group:40 cases).Forty seven residents were selected as controls in a village about 12 km away from the endemic arsenism area.With the informed consent principle,peripheral blood of all respondents was collected in order to analyze DNA methylation and check mRNA.DNA methylation of GSTP1 gene promoter region in peripheral blood was assayed by PCR,and GSTP1 mRNA expression was assayed using real-time quantitative PCR.In addition,other cutaneous specimens originated from 53 cases with arsenism that accepted surgical treatment voluntarily were taken.Of these specimens,general pathological changes were 28 cases,precancerous 20 cases and cancerous 5 cases.Skin tissues of 15 cases of non-tumor surgery patients without abnormal pathological changes were as control group.GSTP1 protein expression in the skin tissue was detected using immunohistochemistry (IHC).Results Among different groups of arsenic poisoning,the positive rate of DNA methylation of GSTP1 gene was 28.57％(12/42) in the mild group,57.10％ (23/41) in the moderate group and 65.00％ (26/40) in the severe group.Compared with the control group (6.38％,3/47),the difference was statistically significant (x2 =7.792,26.000,33.412,all P ＜ 0.01).Among different groups of arsenic poisoning diagnosed by dermapathology,the positive rate of DNA methylation of GSTP1 gene was 21.43％(6/28) in the general pathological change group,50.00％(10/20) in the precancerous group and 80.00％(4/5) in the cancerous group.Compared with the control group(6.67％,1/15),the difference was statistically significant (x2 =3.562,7.468,10.756,all P ＜ 0.05).It showed that the positive rate of DNA methylation of GSTP1 gene increased with aggravation of the disease and dermatic lesion of arsenism (tendency x2 =38.239,x2 =13.659,all P ＜ 0.01).Compared with the control group(0.184 26),the expressions of GSTP1 mRNA in peripheral blood in moderate (0.087 77) and severe arsenic poisoning groups (0.056 93) were significantly reduced(all P ＜0.01),and that of severe group was significantly lower than that of the moderate group (P ＜ 0.01) ; compared with the control group(0.338 45) and the general lesion group(0.276 74),GSTP1 mRNA expression was significantly reduced in precancerous lesion group(0.104 81) and cancerous group(0.043 70),in which the cancerous group was significantly lower than that of the precancerous lesions.The difference of skin tissue GSTP1 protein expression rate between groups was statistically significant (x2 =20.948,P ＜ 0.05),in which the difference between the precancerous lesion group(65.00％,13/20),the cancer group (40.00％,2/5) and the control group(100.00％,15/15)was statistically significant (x2 =12.183,11.778,P ＜ 0.01).Spearman correlation analysis showed that the degree of skin lesion and the level of GSTP1 protein expression was negatively correlated (r =-0.520,P ＜ 0.05).Groups were divided according to DNA methylation of GSTP1 gene,and the mRNA and protein expression of GSTP1 in methylation group(0.038 40,57.14％) was significantly lower compared with that of unmethylated group(0.187 07,95.74％; Z =9.032,x2 =23.134,all P ＜ 0.01).Conclusions Arsenism may lead to DNA methylation of human GSTP1 gene promoter region,thereby inhibiting expression of mRNA and protein.GSTP1 gene plays an important role in arsenism or carcinogenic process.

Relationship between glutathione S-transferase GSTO 1 Glu155 △Glu genetic polymorphism and arsenic poisoning caused by coal-burning / 中国地方病学杂志

ObjectiveTo investigate glutathione S-transferase GSTO 1 Glu155△Glu genetic polymorphism and risks of arsenic poisoning caused by coal-burning in Guizhou.Methods GSTO1 Glu155 △Glu gene polymorphism was analyzed by polymerase chain reaction-with confronting two-pair primers among one hundred and thirty arsenic poisoning patients and one hundred and thirty healthy controls.The results were verified by DNA sequencing.The association between different genotypes and arsenic poisoning was analyzed by unconditional Logistic regression model.ResultsThe results of Glu/Glu and Glu/△Glu genotype detected by this method were consistent with those of DNA sequencing.The frequencies of GSTO1 Glu/Glu genotype and Glu/△Glu genotype were 94.85％(92/97) and 5.15％(5/97) in the patients,99.15％(117/118) and 0.85％(1/118) in the controls,respectively.The difference was statistically significant(x2 =3.896,P ＜ 0.05).△Glu/△Glu genotype was not found in both patients and controls.After age and sex adjusting,GSTO1 Glu155 △Glu polymorphism was found to be a risk factor of arsenic poisoning [odds ratio (OR) =1.85,95％ confidence interval (CI):1.39 - 17.48].ConclusionsThe study finds that GSTO1 Glu 155 △ Glu polymorphism is associated with risk of arsenic poisoning.The relationship between them should be further studied through increasing sample size.

Comparative analysis of environmental risk factors in nine years in an area polluted by arsenic coal-burning in Guizhou Province / 中国地方病学杂志

Objective To comparatively analyze the changes of environmental risk factors in 9 years in an area polluted by arsenic coal-burning in Xingren County of Guizhou Province,in order to provide evidence for reasoning the occurrence and development as well as its effective prevention and control.Methods Epidemiological sampling methods was used to conduct follow-up investigation on 181 arsenism patients who were diagnosed in 1998 in arsenic polluted area.Control group included 65 residents who lived far from polluted area of 12 km.The follow up investigation included age,sexuality,family economic situation,time of use or stop use of arsenic coal, ventilation of the room,desiccation of food etc.Diethyl dithiocarbamate silver(Ag-DDC)method was used to detect arsenic content of coal,soil,air,water and rice,corn,chili;Single factor and multivariate factors non-conditional Logistic regression models were used to analyze exposure factors of patients and related environmental risk factom, and the differences of those in 1998 and 2006 were compared. Results The arsenic content in indoor and outdoor air,coal,chili and corn went down from 0.0880 and 0.0220 mg/m3,397.20,45.07 and 2.64 mg/kg in 1998 to 0.0790 and 0.0070 mg/m3,93.01,3.46 and 1.50 mg/kg in 2006. Arsenic contents of other samples were less than national standard. The analysis of single factor and multivariate factors non-conditional Logistic regression showed that time of using high arsenic coal,age,fluorosis and smoking(x2 = 50.159,12.195,37.69,6.358,P ＜ 0.05 or ＜ 0.01 ) were still the main risk factors for arsenism,while family economic situation was still influential factors (X2 = 4.614,P ＜ 0.05);Ventilation of the room changed from a risk factors at 1998 to an influencing factors at 2006(X2 = 38.093,P ＜ 0.01 ). Single factor non-conditional Logistic regression model analysis showed that food desiccation by arsenic coal-burning and educational level were no longer risk and influencing factors,while food preservation and gender had become influencing factors(x2 = 17.463,11.004,all P ＜ 0.01 ) nine years after. Conclusions Environmental arsenic pollution in arsenism area in Guizhou Province has been obviously improved after nine years. However,the continued existence of low doses of arsenic pollution is still a major cause of failure of controlling arsenism. Time of using high arsenic coal,age,smoking,fluorosis,family economic situation and ventilating room are closely related to the occurrence and the development of arsenism. Prohibition of use of high arsenic coal,furnace improvement,health education and economic development are effective measures

Application of benchmark dose on the study of people's liver dysfunction induced by arsenic-coal burning and its significance / 中国地方病学杂志

Objective To explore the biological exposure limit of liver dysfunction induced by arsenic-coal burning, and screen sensitive biornarkers for its' liver dysfunction monitoring. Methods One hundred and eighteen subjects from the exposed area and 50 control from non-pollution area were studied. Their urinary and hair contents of arsenic were tested as exposure biomarkers by Ag-DDC assay. Total bile acid(TBA, detected by enzymatic cycling method), glutathione S-transferase (GSTs, detected by chemical colorimetry) and γ-glutamyl transpeptidase (γ-GT, detected by colorimetry of diazotization reagent) were used as biomarkers indicating liver cell damage. were used as liver fibrosis biomarkers. The benchmark dose (BMD) and the lower confidence limit of benchmark dose(BMDL) of urinary and hair arsenic were calculated. Sensitivity of each biomarker was estimated according to the BMD and BMDL value. Results The geometric mean of urinary and hair arsenic(98.50 mg/kg Cr, 7.42 mg/kg) μg/L) in the exposed group were significantly higher than urinary and hair arsenic (22.98 mg/kg Cr, 1.28 mg/kg) and each biomarker in the control group(4.63 μmol/L, 13.76 U/L,36.45 U/L,54.62 μg/L,74.45 μg/L,54.81 μg/L, P<0.01). Significant dose-effect relationship existed between urinary and hair arsenic contents and each biomarker. BMD and BMDL value of urinary arsenic was 49.53-101.96 mg/kg Cr and 39.02-70.15 mg/kg Cr, respectively. Those of hair arsenic were 3.04-5.02 mg/kg and 2.36-3.25 mg/kg, respectively. According to BMD and BMDL value of urinary and hair arsenic, the sensitivity of biomarkers decreased in the order of GSTs, TBA and Conclusions According to the lowest BMD and BMDL of urinary and hair arsenic, averaged reference value of urinary and hair arsenic in the local normal population, we suggest urinary 35.0 mg/kg Cr and hair 2.5 mg/kg as their biological exposure limits for those with liver dysfunction induced by arsenic-coal burning. GSTs, TBA, γ-GT and HA, Ⅳ. C, PC-Ⅲ can respectively reflect liver cell damage and liver fibrosis caused by arsenic-coal burning in different degrees, among which, GSTs and HA are the most sensitive biomarkers respectively for liver cell damage and liver fibrosis.